The existence of this child is only known from a mention of it in Mary (Dobbs) Crolius' statement of her Revolutionary War experiences, filed with her war widow's pension application. Shortly after the British had attacked New York, William evacuated his family to safety in New Jersey, and then joined the Contential Army. Mary describes a meeting with her husband in which he "saw my first born for the first time which was only six weeks old". Estimating from her description of being some months after the British attacked New York, this would probably be early 1777. It is not known what happened to this child.